How to scroll to the bottom of a RecyclerView? scrollToPosition doesn't work

I'd like to scroll to the bottom of the RecyclerView list after loading the activity.

GENERIC_MESSAGE_LIST = (ArrayList) intent.getExtras().getParcelableArrayList(ConversationsAdapter.EXTRA_MESSAGE);
conversationView = (RecyclerView) findViewById(R.id.list_messages);
conversationView.setHasFixedSize(true);
conversationViewLayoutManager = new LinearLayoutManager(this);
conversationView.setLayoutManager(conversationViewLayoutManager);
conversationViewAdapter = new ConversationAdapter(GENERIC_MESSAGE_LIST, this);
conversationView.setAdapter(conversationViewAdapter);

conversationView.scrollTo(...) throws an exception about being not supported in RecyclerView, and conversationView.scrollToPosition(...) doesn't seem to do anything.

After the above block of code, I added

conversationView.scrollToPosition(GENERIC_MESSAGE_LIST.size() + 1)

which doesn't work. There are 30 elements in GENERIC_MESSAGE_LIST.

Solution 1:

I was looking at this post to find the answer but... I think everyone on this post was facing the same scenario as me: scrollToPosition() was fully ignored, for an evident reason.

What I was using?

recyclerView.scrollToPosition(items.size());

... what WORKED?

recyclerView.scrollToPosition(items.size() - 1);

Solution 2:

Just set setStackFromEnd=true or setReverseLayout=true so that LLM will layout items from end.

The difference between these two is that setStackFromEnd will set the view to show the last element, the layout direction will remain the same. (So, in an left-to-right horizontal Recycler View, the last element will be shown and scrolling to the left will show the earlier elements)

Whereas setReverseLayout will change the order of the elements added by the Adapter. The layout will start from the last element, which will be the left-most in an LTR Recycler View and then, scrolling to the right will show the earlier elements.

Sample:

final LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getActivity());
linearLayoutManager.setReverseLayout(true);
_listView.setLayoutManager(linearLayoutManager);

See documentation for details.